The invention relates to improvements in apparatus for convoluting or rolling adhesive-coated uniting bands around rod-shaped commodities, especially around groups of coaxial rod-shaped articles of the tobacco processing industry.
Apparatus of the type to which the present invention pertains are disclosed, for example, in commonly owned U.S. Pat. No. 3,483,873 granted Dec. 16, 1969 to Alfred Hinzmann for "Apparatus for making holes in tobacco rods or the like" and in commonly owned U.S. Pat. No. 3,527,234 granted Sep. 8, 1970 to Alfred Hinzmann for "Apparatus for convoluting uniting bands around rod-shaped articles". As a rule, such convoluting or rolling apparatus comprise a rotary drum-shaped conveyor which carries a series of adhesive-coated uniting bands, each adjacent a group of rod-shaped articles, and a stationary rolling member which defines with the conveyor a gap wherein the groups of coaxial rod-shaped articles are caused to roll about their own axes in order to thereby convolute the uniting bands therearound. This results in conversion of the groups and of the respective uniting bands into smokers' articles (particularly filter cigarettes of multiple unit length) wherein the uniting band forms a tube surrounding the abutting ends of the respective rod-shaped articles. For example, each filter cigarette can comprise two plain cigarettes of unit length flanking a filter mouthpiece of double unit length, and a tube which is the converted uniting band and surrounds the filter mouthpiece as well as the adjacent inner end portions of the plain cigarettes. Many filter tipping machines which employ such rolling or convoluting apparatus are known as MAX and MAX S (both manufactured by the assignee of the present application).
The output of filter tipping machines is on the increase, practically from year to year. Each such increase of output invariably creates problems in certain parts of filter tipping machines. For example, the previously used testing units must be redesigned, or entirely new testing units must be invented, in order to be capable of adequately monitoring the condition of filter cigarettes which are turned out at the rate of many thousands per minute. Analogously, conventional apparatus which are used in such machines to roll uniting bands around groups of plain cigarettes and filter mouthpieces often cannot do the job without defacing, damaging and/or otherwise adversely affecting the appearance and/or other desirable characteristics of the products. For example, abrupt rolling of successive groups of coaxial rod-shaped articles about their axes from zero rolling speed to maximum rolling speed can result in the escape of large quantities of tobacco particles at the exposed ends of plain cigarettes, and abrupt engagement with a stationary rolling surface can cause damage to the uniting bands and/or to the wrappers of individual rod-shaped articles of the groups.